This is a classic GMAT trap that tests your ability to work systematically with inequalities and Roman numeral statements. Many students rush into evaluating the statements without first establishing the constraint on x.
Strategic Framework:Step 1: Solve the Core ConstraintGiven: (\frac{4-7x}{3} > 3)
Multiply both sides by 3: (4-7x > 9)
Subtract 4: (-7x > 5)
Divide by -7 (flip the inequality): (x < -\frac{5}{7})
Wait - this means (x < -5), not (x > -5).
Critical insight: The constraint severely limits our x values.Step 2: Systematic Statement EvaluationNow that we know (x < -5), let's check what MUST always be true:
Statement I: (x > 5)
Since (x < -5), this can never be true.
FALSEStatement II: (|x + 3| > 2)
If (x < -5), then (x + 3 < -2)
Since (x + 3) is negative and less than -2: (|x + 3| = -(x + 3) > 2) ✓
TRUEStatement III: (-(x + 5)) is positive
Since (x < -5), we have (x + 5 < 0)
Therefore (-(x + 5) > 0) ✓
TRUEAnswer: D) II and III onlyThe key insight here is recognizing that "must be true" problems require you to find what's
always true given the constraint, not what's
sometimes true. This pattern appears frequently in GMAT inequalities.
For the complete breakdown showing the systematic approach to all Roman numeral inequality problems, plus the 3 most common trap patterns students fall into:
https://neuron.e-gmat.com/quant/questions/if-4-7-x-3-which-of-the-following-must-be-true-1617.html